How is it possible that I have never read The Wonderful Wizard of Oz? Absolutely delightful. It's especially interesting coming at the book having only seen the movie (and, I suppose, seen Wicked and read Gregory Maguire's books), to see how the writers of The Wizard of Oz screenplay manipulated the book to make it fit the film format. They did an amazingly good job of it.
Going to have to read all these books now (and they're all free on Amazon).